The mechanical power for deploying high lift devices in many commercial airplanes today involves very high speed rotational torque. Such torque is generated by a power drive unit, or system power source, and transmitted via torque tubes forming a driveline along the wing to the most outboard rotary actuator to be powered. These rotary actuators are actually gear speed reducers that reduce the rotational speed from about 700-1000 rpm to about 1-10 rpm. This increases the available torque correspondingly so that the high lift devices may be deployed with appropriate force and speed of deployment, even under adverse conditions such as ice buildup on the wing leading edge.
In some commercial airplanes, it has been possible to place the drivelines such that they align with the rotary actuator. In other airplanes, this has not been possible, and it has been necessary to utilize an "offset" gearbox to transmit the rotary power from the centerline of the driveline, forwardly to the centerline of the rotary actuator. Hence, the term "offset gearbox" has been applied to the gearbox of this invention.
A problem in this type of offset gearbox is that, due in part to its complexity, and because aircraft safety is a concern, it can be costly and time consuming to perform inspections on and to perform required maintenance activities.